94 GHz integrated monopulse antennas

A monolithic direction-finding monopulse antenna for applications at 94 GHz has been designed. The structure consists of a single-dipole suspended in one plane of an integrated horn cavity to obtain the sum pattern, and an anti-parallel pair of dipoles suspended in a different plane of the same horn cavity to achieve the difference pattern. The resonant input impedances of the sum and difference antennas were measured using a microwave model. The resonant input impedances are 53 Omega and 43 Omega , respectively. with a bandwidth +or-8% of the center frequency for a voltage standing wave ratio of 2. Microwave patterns of each antenna were measured at 3.3 GHz, and the difference antenna produced a sharp null below -25 dB across at +or-10% bandwidth.<<ETX>>